public class SortingHelper {

    private SortingHelper(){}

    public static <E extends Comparable<E>> boolean isSorted(E[] arr){

        for(int i = 1; i<arr.length; i++)
            if(arr[i-1].compareTo(arr[i]) > 0)
                return false;
        return true;
    }

    public static  <E extends Comparable<E>> void sortTest(String sortname,E[] arr){
        long startTime = System.nanoTime();
        if(sortname.equals("SelectionSort"))
            SelectionSort.sort(arr);
        else if(sortname.equals("InsertionSort"))
            InsertionSort.sort(arr);
        else if(sortname.equals("InsertionSort2"))
            InsertionSort.sort2(arr);

        long endTime = System.nanoTime();

        double time = (endTime - startTime) /1000000000.0;
        if(!SortingHelper.isSorted(arr))
            throw new RuntimeException(sortname + " Error!");
        System.out.printf("%s, n = %d : %f s%n",sortname,arr.length,time);
    }
}
